Growth Failure (Short Stature)

Disclaimer: > [!WARNING] Medical Disclaimer: This content is for educational and informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. Medical guidelines and best practices change rapidly; users should verify information with current local protocols.

1. Clinical Overview

Summary

Growth failure, or short stature, is defined as height below -2 standard deviations (SD) from the population mean for age and sex, or height below the 2nd centile on appropriate growth charts. [1,2] It represents a common paediatric presentation, accounting for approximately 3% of children in the general population and up to 10% of referrals to paediatric endocrinology clinics. [3]

The vast majority of short children are constitutionally normal variants - either familial short stature (FSS) or constitutional delay of growth and puberty (CDGP). [4] However, short stature may also represent the presenting feature of significant underlying pathology, including growth hormone deficiency, Turner syndrome, skeletal dysplasias, chronic systemic disease, or genetic syndromes. [5]

The clinical challenge lies in distinguishing normal variation from pathological causes, while avoiding over-investigation of healthy children. A systematic approach based on auxological assessment (detailed growth measurements and pattern analysis) forms the cornerstone of evaluation. [6]

Key Definitions (WHO/CDC Growth Standards)

Absolute Height Criteria:

• Short stature: Height < -2 SD (2nd centile) for age and sex
• Severe short stature: Height < -3 SD (0.4th centile)
• Normal stature: Height between -2 SD and +2 SD (2nd-98th centile)
• Tall stature: Height >+2 SD (98th centile)

Growth Velocity Criteria:

• Growth faltering: Height velocity less than 25th centile for age over 6-12 months
• Centile crossing: Drop down through ≥2 major centile spaces (e.g., 50th → 9th)
• Static growth: Crossing ≥3 centile spaces or plateauing

Clinical Pearls

Auxology Before Biochemistry: The pattern of growth on serial measurements is more informative than any single blood test. Always plot height, weight, and head circumference on appropriate charts (UK-WHO, CDC, or syndrome-specific charts). [7]

Three Key Questions:

1. Is the child truly short (below -2 SD)?
2. Is the growth velocity normal (parallel to centiles)?
3. Is height appropriate for mid-parental height?

Normal Variants Have Normal Velocity: Children with familial short stature or constitutional delay grow parallel to centiles (normal velocity). Pathological causes typically show progressive centile crossing.

---

2. Epidemiology

Prevalence and Distribution

Age and Sex Distribution

• Peak age of presentation: 5-8 years (school entry triggers parental concern) and early adolescence (delayed puberty becomes apparent)
• Sex ratio: Boys referred more frequently than girls (3:1), partly due to greater psychosocial impact and higher prevalence of CDGP in males [11]
• Ethnic variation: Growth charts should be ethnicity-appropriate; mean heights vary between populations

Risk Factors for Pathological Short Stature

• Perinatal factors: Small for gestational age (SGA), intrauterine growth restriction (IUGR), prematurity [12]
• Family history: Parental short stature, consanguinity, familial syndromes
• Chronic disease: Coeliac disease, inflammatory bowel disease, chronic kidney disease, congenital heart disease
• Medications: Prolonged corticosteroid therapy, stimulant medications for ADHD
• Psychosocial deprivation: Neglect, emotional abuse (psychosocial short stature)

---

3. Aetiology and Pathophysiology

Growth is a complex, multi-factorial process regulated by genetic, hormonal, nutritional, and environmental factors. Disturbances at any level of the growth axis can result in short stature.

Causes of Short Stature by Category

A. Normal Variants (80-90% of cases) [4,8]

B. Endocrine Causes (5-10%)

1. Growth Hormone Deficiency (GHD) [9]

• Isolated GHD: Congenital (GH1/GHRHR mutations, pituitary hypoplasia) or acquired (craniopharyngioma, radiotherapy, trauma)
• Multiple pituitary hormone deficiency (MPHD): Associated with midline defects, septo-optic dysplasia, genetic causes (PROP1, POU1F1 mutations)
• Pathophysiology: GH promotes linear growth via hepatic IGF-1 production; deficiency results in reduced chondrocyte proliferation at growth plates

2. Hypothyroidism [13]

• Primary (autoimmune thyroiditis) or central (TSH deficiency)
• Thyroid hormone essential for GH secretion and growth plate function
• Typically causes growth faltering with delayed bone age and weight gain

3. Cushing Syndrome

• Excess glucocorticoids (exogenous or endogenous)
• Inhibit GH secretion and have direct catabolic effects on growth plates

4. Precocious Puberty

• Early sex steroid exposure accelerates bone maturation
• Initial tall stature followed by premature growth plate fusion and short final height

C. Chromosomal/Genetic Syndromes (5-10%)

1. Turner Syndrome (45,X and variants) [10]

• Most common sex chromosome disorder causing short stature in females
• Haploinsufficiency of SHOX gene (on X chromosome) impairs growth plate function
• Average untreated adult height: 143-148 cm
• Associated features: ovarian dysgenesis, cardiac anomalies (coarctation, bicuspid aortic valve), renal anomalies, lymphoedema

2. Noonan Syndrome

• PTPN11 mutations (RAS/MAPK pathway)
• Features: short stature, webbed neck, pectoral deformity, pulmonary stenosis

3. Silver-Russell Syndrome

• Intrauterine growth restriction, postnatal growth failure, asymmetry
• Chromosome 11p15 or maternal UPD7

4. Prader-Willi Syndrome

• Paternal 15q11-13 deletion or maternal UPD
• Short stature, hypotonia, hyperphagia, obesity

D. Skeletal Dysplasias (3-5%)

Disproportionate Short Stature:

• Achondroplasia: FGFR3 mutation; rhizomelic limb shortening, macrocephaly, normal intelligence
• Hypochondroplasia: Milder FGFR3 mutations
• Spondyloepiphyseal dysplasias: Primarily truncal involvement

Proportionate Short Stature:

• Dyggve-Melchior-Clausen syndrome
• Multiple epiphyseal dysplasias

E. Small for Gestational Age (SGA) without Catch-up [12]

• 10% of SGA infants fail to achieve catch-up growth by age 2-4 years
• Mechanisms: placental insufficiency, genetic factors, maternal factors (smoking, malnutrition)
• Licensed indication for GH therapy in many countries

F. Chronic Systemic Disease

G. Psychosocial Deprivation (Psychosocial Short Stature)

• Severe emotional neglect/abuse → functional GH deficiency
• Mechanism: Chronic stress → dysregulation of HPA axis → impaired GH secretion
• Dramatic catch-up growth when removed from adverse environment

Exam Detail: Molecular Pathophysiology of Growth Regulation:

The GH-IGF axis is the primary hormonal regulator of postnatal linear growth:

1. Hypothalamic regulation: GHRH (stimulates) and somatostatin (inhibits) regulate pituitary GH secretion in pulsatile fashion (peaks during deep sleep)

2. GH effects:

   • Direct: Lipolysis, insulin antagonism (diabetogenic)
   • Indirect (via IGF-1): Stimulates hepatic and local IGF-1 production → chondrocyte proliferation at growth plates, protein synthesis, bone mineralization

3. IGF-1 binding proteins: IGF-1 circulates bound to IGFBP-3 and acid-labile subunit (ALS), prolonging half-life and modulating bioavailability

4. Growth plate biology:

   • Epiphyseal growth plates consist of resting, proliferative, and hypertrophic chondrocyte zones
   • GH/IGF-1 stimulates clonal expansion in proliferative zone
   • Thyroid hormone, sex steroids, and paracrine factors (BMPs, FGFs, WNTs) coordinate chondrocyte differentiation
   • Sex steroids initially accelerate growth but ultimately cause epiphyseal fusion (via estrogen, even in males)

5. SHOX gene: Short stature homeobox-containing gene on pseudoautosomal region of X/Y chromosomes

   • Mutations or deletions cause Leri-Weill dyschondrosteosis (mesomelic limb shortening)
   • Haploinsufficiency in Turner syndrome contributes to short stature

---

4. Clinical Assessment: The Auxological Approach

The "Auxology-First" Principle

Auxology is the science of human growth measurement. A comprehensive auxological assessment can identify 70-80% of diagnoses before any laboratory investigations. [6,7]

Step 1: Detailed History

Growth History

• Birth parameters: Birth weight, length, head circumference, gestational age
• Postnatal growth pattern: Ask parents to bring red book (Personal Child Health Record)
• Previous measurements: School nurse measurements, GP records
• Pubertal development: Age of onset of thelarche (girls), testicular enlargement (boys), menarche, growth spurt timing

Nutritional History

• Dietary intake: Adequacy, restrictive diets (vegan, avoidance)
• Gastrointestinal symptoms: Diarrhoea, constipation, abdominal pain, bloating (coeliac disease, IBD)
• Appetite and feeding behaviour

Systemic Review

• Headaches, visual disturbance: Craniopharyngioma, pituitary tumour
• Polyuria, polydipsia: Craniopharyngioma causing diabetes insipidus
• Hypothyroid symptoms: Cold intolerance, constipation, fatigue, dry skin
• Hypoglycaemia: Cortisol/GH deficiency
• Chronic disease symptoms: Respiratory, cardiac, renal, gastrointestinal

Family History

• Parental heights (measure if possible, don't rely on self-report)
• Family history of short stature, delayed puberty ("late bloomer" in father suggests CDGP)
• Consanguinity (autosomal recessive conditions)
• Ethnicity (use appropriate growth charts)

Developmental and Educational History

• Developmental milestones: Delay may suggest genetic syndrome or global disorder
• School performance: Learning difficulties (e.g., Noonan, Turner syndromes)

Psychosocial History

• Home environment: Neglect, emotional abuse (psychosocial short stature)
• Impact on child: Bullying, self-esteem, social functioning

Step 2: Accurate Anthropometry

Height Measurement Technique

• Stadiometer (wall-mounted preferred over portable)

• Technique:

  • Remove shoes and hair accessories
  • Heels together against wall, back straight
  • Gentle upward traction on mastoid processes ("stretch")
  • Eyes looking straight ahead (Frankfurt plane horizontal)
  • Measure to nearest 0.1 cm
  • Three measurements, record median (reduces error)

• Under 2 years: Supine length measurement (add 0.5 cm to convert to standing height equivalent)

Weight and BMI

• Plot weight on centile chart
• Calculate BMI z-score: Low BMI suggests malnutrition/malabsorption; high BMI suggests Cushing, hypothyroidism, Prader-Willi

Head Circumference

• Measure until age 4 years
• Microcephaly suggests syndromic cause or CNS pathology
• Macrocephaly: Achondroplasia, hydrocephalus, storage disorders

Growth Chart Plotting [7]

Use appropriate charts:

• UK: UK-WHO growth charts (0-4 years WHO standards, 4-20 years UK 1990 reference)
• USA: CDC 2000 growth charts
• Syndrome-specific: Turner, Down, achondroplasia charts available

Plot:

1. Height for age (current centile position)
2. Weight for age
3. BMI for age
4. Height velocity (if serial measurements available): Plot cm/year against age-specific velocity charts
5. Mid-parental height (MPH) / Target height range

Step 3: Mid-Parental Height (MPH) Calculation

MPH estimates the genetic height potential based on parental heights. [14]

Formula:

Boys: MPH = [(Father's height + Mother's height + 13 cm) / 2]

Girls: MPH = [(Father's height + Mother's height - 13 cm) / 2]

Target height range: MPH ± 10 cm (approximately ± 1.5 SD)

• Interpretation:
  • Child's height within target range → Familial short stature likely (if parents short)
  • Child's height below target range → Suggests pathology
  • Child's height above target range → Suggests familial tall stature or early maturation

Limitations:

• Assumes parents achieved their genetic potential (may not be true if parents had childhood illness or malnutrition)
• Less accurate in consanguineous families or with ethnic mixing

Step 4: Clinical Examination

General Inspection

• Appearance: Well or unwell, thin/obese, age-appropriate?
• Dysmorphic features: Syndromic facies (see below)
• Body proportions:
  • "Sitting height vs leg length: Measure sitting height; calculate sitting height/height ratio"
  • Upper segment (crown to pubis) vs lower segment (pubis to floor)
  • Arm span vs height (arm span > 5 cm greater than height suggests spinal dysplasia)
  • Disproportionate short stature suggests skeletal dysplasia

Syndromic Features to Recognize

Cardiovascular Examination

• Turner syndrome: Coarctation of aorta (radio-femoral delay, BP difference), bicuspid aortic valve (ejection systolic murmur)
• Noonan syndrome: Pulmonary stenosis (ejection systolic murmur left sternal edge)
• Congenital heart disease: Cyanosis, clubbing, murmurs

Abdominal Examination

• Hepatosplenomegaly (storage disorders, chronic liver disease)
• Distension (coeliac disease, chronic constipation in hypothyroidism)

Pubertal Staging (Tanner Staging) [15]

Critical for differentiating CDGP from GHD:

Boys:

• Testicular volume (Prader orchidometer): ≥4 ml indicates pubertal onset
• Genitalia staging (G1-5)
• Pubic hair (PH1-5)

Girls:

• Breast development (B1-5)
• Pubic hair (PH1-5)
• Menarche (average age 12.5 years in UK)

Delayed puberty:

• Boys: No testicular enlargement by age 14 years
• Girls: No breast development by age 13 years

Interpretation:

• Short stature with delayed puberty → CDGP or hypogonadotropic hypogonadism
• Short stature with normal/early puberty → Consider GHD, skeletal dysplasia, chronic disease

Neurological Examination

• Visual fields (craniopharyngioma/pituitary tumour causing bitemporal hemianopia)
• Optic fundi (papilloedema)
• Gait and tone (skeletal dysplasia may affect mobility)

---

5. Differential Diagnosis by Pattern Recognition

Pattern A: Short Stature with Normal Growth Velocity

Child tracking below but parallel to centiles, bone age normal or mildly delayed

Diagnosis: Familial Short Stature (FSS)

• Both parents short (MPH below -2 SD)
• Child's height consistent with MPH
• Normal growth velocity (4-6 cm/year age 4-10)
• Bone age = chronological age (±1 year)
• Puberty at normal time
• Final height = MPH (short but normal for family)

Management: Reassurance, no investigations needed if classic presentation

---

Pattern B: Short Stature with Delayed Bone Age and Delayed Puberty

Child tracking parallel to centiles but at lower level, bone age delayed > 2 years

Diagnosis: Constitutional Delay of Growth and Puberty (CDGP)

• Classic pattern: "Late bloomer"
• Family history of delayed puberty (especially father)
• Height may be below -2 SD in early adolescence
• Growth velocity normal (4-6 cm/year) until expected puberty
• Bone age delayed 2-4 years behind chronological age
• Puberty delayed (boys: no testicular enlargement by 14 years; girls: no breast development by 13 years)
• Final adult height normal (achieved 2-4 years later than peers)

Psychosocial impact: Significant in boys (teasing, poor self-esteem, delayed dating)

Management:

• Reassurance and monitoring
• Consider short course of testosterone (boys) or oxandrolone to induce temporary acceleration and boost confidence [16]

---

Pattern C: Short Stature with Reduced Growth Velocity (Centile Crossing)

Child progressively falling down centiles (crossing ≥2 centile spaces)

Indicates PATHOLOGY – requires full investigation

Causes:

1. Growth hormone deficiency
2. Hypothyroidism
3. Chronic systemic disease (coeliac, CKD, IBD, cardiac, respiratory)
4. Cushing syndrome
5. Turner syndrome
6. Psychosocial deprivation

---

Pattern D: Disproportionate Short Stature

Sitting height/height ratio abnormal; arm span ≠ height

Diagnosis: Skeletal Dysplasia

Short limbs (rhizomelic or mesomelic):

• Achondroplasia, hypochondroplasia, Leri-Weill dyschondrosteosis (SHOX mutations)

Short trunk:

• Spondyloepiphyseal dysplasias

Management: Skeletal survey (X-rays), genetics referral, multidisciplinary management

---

Pattern E: Short Stature from Birth (SGA)

Birth weight and/or length < -2 SD for gestational age; 90% catch up by age 2-4 years

Diagnosis: SGA without catch-up growth [12]

Causes: Placental insufficiency, IUGR, Silver-Russell syndrome, maternal smoking/alcohol

Licensed indication for GH therapy in many countries if height remains < -2.5 SD at age 4 years

---

6. Investigations

The "Auxology-First, Biochemistry Second" Principle

Do not routinely screen all short children. Investigate selectively based on:

1. Abnormal growth velocity (centile crossing)
2. Height < -3 SD
3. Height disproportionate to MPH
4. Dysmorphic features or syndromic suspicion
5. Symptoms/signs of chronic disease

First-Line Investigations (Screening)

Purpose: Identify common treatable causes and chronic disease

Karyotype (all short girls with no clear diagnosis): Turner syndrome (45,X or mosaicism)

Bone age X-ray (left hand and wrist):

• Greulich-Pyle atlas (most widely used): Compares X-ray to reference standards [19]
• Tanner-Whitehouse method (more precise but time-consuming)
• Interpretation:
  • "Bone age = chronological age ± 1 year: Normal (FSS)"
  • "Bone age delayed > 2 years: CDGP, hypothyroidism, GHD, malnutrition"
  • "Bone age advanced: Obesity, precocious puberty, Cushing (mild advancement)"

Second-Line Investigations (Specialist Paediatric Endocrinology)

Indications:

• Low IGF-1/IGFBP-3
• Progressive centile crossing
• Clinical suspicion of GHD (midline defects, neonatal hypoglycaemia, history of CNS irradiation)

Growth Hormone Provocation Tests

Rationale: GH secretion is pulsatile; random GH levels are unhelpful. Provocation tests assess peak GH response to stimuli. [9]

Stimuli used (perform 2 different tests to reduce false positives):

1. Insulin tolerance test (ITT) - "gold standard" (induces hypoglycaemia)
2. Glucagon stimulation test
3. Arginine stimulation test
4. Clonidine stimulation test
5. GHRH + arginine test

GH deficiency diagnosed if:

• Peak GH less than 7 μg/L on 2 different tests (some centres use less than 10 μg/L threshold)

Severe GHD: Peak GH less than 3 μg/L

Caution:

• Tests are not perfect (false positives/negatives occur)
• Diagnosis should always integrate clinical context, auxology, and MRI findings
• Priming with sex steroids may be needed in pubertal-age children to avoid false-positive results [9]

MRI Pituitary (if GHD confirmed or suspected MPHD)

Identifies:

• Pituitary hypoplasia/aplasia
• Ectopic posterior pituitary (bright spot in abnormal location)
• Interrupted pituitary stalk
• Septo-optic dysplasia (absent septum pellucidum, optic nerve hypoplasia)
• Craniopharyngioma or other tumours
• Empty sella syndrome

Classic triad of congenital GHD: Pituitary hypoplasia + ectopic posterior pituitary + interrupted stalk

Additional Pituitary Function Tests (if MPHD suspected)

• Cortisol (0900 hrs) or short synacthen test: Assess ACTH deficiency
• LH, FSH, testosterone/oestradiol: Assess gonadotrophin deficiency
• Prolactin: Assess lactotroph function (may be elevated with stalk compression)
• Paired serum and urine osmolality: Assess ADH (diabetes insipidus)

Third-Line Investigations (Specialist Genetics/Skeletal Dysplasia)

If syndromic features or skeletal dysplasia suspected:

• Karyotype or microarray (Turner, Noonan, other chromosomal disorders)
• Targeted genetic testing: SHOX gene (Leri-Weill), FGFR3 (achondroplasia), PTPN11 (Noonan), etc.
• Whole exome/genome sequencing (complex presentations)
• Skeletal survey (AP and lateral spine, pelvis, long bones, skull): Identifies dysplasias
• Cardiac echo and renal ultrasound (Turner syndrome - coarctation, bicuspid aortic valve, horseshoe kidney)

---

7. Management

Management is cause-specific. The following outlines management of the commonest presentations.

A. Familial Short Stature (FSS)

No treatment indicated if:

• Growth velocity normal
• Child tracking parallel to centiles
• Height within target range (MPH ± 10 cm)

Management:

1. Reassurance: Explain child is healthy, growing normally for family
2. Monitor growth: Annual height measurement until growth complete
3. Address psychosocial concerns: School, bullying, self-esteem
4. Counsel regarding final height: Likely to be similar to short parent(s)

GH therapy:

• NOT routinely recommended (minimal height gain, high cost, medicalization of normality)
• In some countries, GH licensed for "idiopathic short stature" if height < -2.25 SD and predicted adult height severely short; controversial due to ethical concerns [20]

---

B. Constitutional Delay of Growth and Puberty (CDGP)

Reassurance is the primary intervention for most cases.

Management:

1. Detailed explanation: Show bone age X-ray, explain delayed maturation tempo, predict adult height (will be normal)
2. Reassurance: Provide growth prediction charts showing expected pubertal growth spurt (just later than peers)
3. Monitor: 6-monthly height measurements, reassess bone age annually
4. Psychological support: Significant psychosocial impact, especially in boys (teasing, exclusion from sports)

Short-term hormone therapy (if severe psychosocial impact): [16]

Boys:

• Testosterone (low-dose IM injection): 50-100 mg IM monthly for 3-6 months
  • Induces temporary growth acceleration and virilisation
  • Boosts confidence while awaiting natural puberty
  • Does NOT compromise final height

Girls:

• Low-dose oestrogen (oral ethinylestradiol 2-5 μg daily) for 3-6 months
  • Less commonly used (girls tolerate delay better psychosocially)

Alternative: Oxandrolone (anabolic steroid)

• Low-dose: 0.05 mg/kg/day (max 2.5 mg/day)
• Accelerates growth, advances bone age modestly
• Used off-label in some centres

When to reconsider diagnosis:

• If puberty has not commenced by age 15-16 (boys) or 14-15 (girls), reassess for hypogonadotropic hypogonadism

---

C. Growth Hormone Deficiency (GHD)

Recombinant human growth hormone (rhGH) therapy is highly effective and licensed for GHD. [9,20]

Indications for GH Therapy

Licensed indications (vary by country; below are typical):

1. Growth hormone deficiency (confirmed by provocation tests + low IGF-1)
2. Turner syndrome
3. Chronic renal insufficiency (pre-dialysis/transplant)
4. Prader-Willi syndrome
5. Small for gestational age (SGA) without catch-up by age 4
6. SHOX gene deficiency
7. Noonan syndrome (some countries)

Unlicensed/controversial:

• Idiopathic short stature (ISS): Height < -2.25 SD with no identifiable cause; controversial due to cost, medicalization of normality, modest height gains (4-7 cm) [20]

GH Treatment Protocol

Dose:

• GHD: 0.025-0.035 mg/kg/day (higher doses for Turner, SGA)
• Subcutaneous injection, daily, typically at bedtime (mimics physiological nocturnal GH peak)

Monitoring:

• Height and weight: Every 3-6 months
• Growth velocity: Should increase to 8-12 cm/year in first year (good response)
• IGF-1 levels: Monitor to ensure in upper-normal range (avoid over-treatment)
• Bone age: Annually
• Thyroid function: Annually (GH can unmask hypothyroidism)
• HbA1c or glucose: Monitor for insulin resistance

Duration:

• Continue until:
  • Growth velocity less than 2 cm/year AND
  • Bone age > 14 years (girls) or > 16 years (boys)
• Transition to adult endocrinology for assessment of GH replacement in adulthood (if severe GHD)

Complications of GH Therapy

Safety:

• Cancer risk: No evidence of increased primary cancer risk in children without pre-existing tumours; monitor for recurrence in those with prior CNS tumours (craniopharyngioma)

---

D. Turner Syndrome

Multidisciplinary management required (paediatric endocrinology, cardiology, audiology, gynaecology, psychology). [10]

Growth management:

1. GH therapy: Start early (age 4-6 years if height faltering)
   • Dose: Higher than GHD (0.045-0.050 mg/kg/day)
   • Improves final height by 5-10 cm on average
2. Oxandrolone (low-dose anabolic steroid): May be added in late childhood/early adolescence to further boost height (controversial)
3. Oestrogen replacement (for pubertal induction):
   • Start age 11-12 years (low-dose, gradually increase)
   • Timing critical: Too early → premature epiphyseal fusion (compromises final height); too late → delayed bone health, psychosocial impact

Cardiac surveillance:

• Echo at diagnosis, then 3-5 yearly (screen for coarctation, bicuspid aortic valve, aortic root dilatation)
• BP monitoring: Risk of hypertension

Renal ultrasound: Screen for horseshoe kidney, renal anomalies

Hearing: Audiology assessment (risk of conductive/sensorineural hearing loss)

Fertility: Counsel regarding ovarian dysgenesis; offer oocyte cryopreservation if residual function

---

E. Small for Gestational Age (SGA) without Catch-up

GH therapy indications (varies by country): [12]

• Birth weight or length < -2 SD for gestational age
• Failure to achieve catch-up growth by age 2-4 years
• Current height < -2.5 SD at age 4 years or later

Dose: 0.035-0.067 mg/kg/day

Monitoring: As per GHD

---

F. Hypothyroidism

Levothyroxine replacement:

• Restores normal growth velocity within 3-6 months
• Catch-up growth occurs

---

G. Coeliac Disease

Gluten-free diet:

• Restores growth in most children within 6-12 months [17]

---

H. Chronic Kidney Disease

Optimize nutrition, correct acidosis, treat renal osteodystrophy

GH therapy (licensed for CKD):

• Dose: 0.045-0.050 mg/kg/day
• Continue until transplant (may continue post-transplant in some cases)

---

I. Psychosocial Short Stature

Remove child from adverse environment (child protection measures):

• Dramatic catch-up growth typically occurs
• GH axis normalizes spontaneously

---

8. Complications and Long-term Outcomes

Psychosocial Impact of Short Stature

Quality of life:

• Short stature (especially extreme < -3 SD) associated with teasing, bullying, reduced self-esteem
• Greater impact in boys than girls (societal expectations)
• Impact increases during adolescence

Educational and vocational outcomes:

• Generally normal if short stature is isolated
• May be impaired if associated with learning difficulties (e.g., Turner, Noonan syndromes)

Adult psychosocial adjustment:

• Most adults with short stature (including untreated FSS and CDGP) adjust well
• Severe short stature (< -3 SD) may affect dating, employment in certain fields

Metabolic Consequences of GHD (Untreated)

Adults with untreated GHD (from childhood):

• Increased body fat (especially visceral)
• Reduced lean body mass
• Dyslipidaemia
• Reduced bone mineral density (osteoporosis risk)
• Impaired quality of life, reduced exercise capacity

Transition to adult GH therapy: Severe GHD diagnosed in childhood should be re-tested in late adolescence; if persistent, continue GH (different dose for adult indications)

---

9. Prognosis and Final Height Prediction

Height Prediction Methods

1. Bone Age Method (Bayley-Pinneau, Greulich-Pyle tables):

• Uses current height and bone age to predict adult height
• Assumes normal pubertal progression
• Less accurate in pathological conditions

2. Mathematical Models (Tanner-Whitehouse Mark II):

• Incorporates height, bone age, chronological age, mid-parental height
• More accurate but complex

3. Syndrome-Specific Predictions:

• Turner syndrome untreated: 143-148 cm
• Turner syndrome + GH: 150-158 cm (average gain 5-10 cm)
• GHD untreated: Highly variable, often less than 150 cm in males
• GHD treated: Near-normal final height if started early

---

10. Key Guidelines and Evidence

Major Society Guidelines

1. Growth Hormone Research Society (GRS) 2016: Diagnosis and treatment of GHD in children [9]
2. Pediatric Endocrine Society 2019: Evaluation of short stature [2]
3. European Society for Paediatric Endocrinology (ESPE): Turner syndrome consensus 2017 [10]
4. NICE NG203 (2022): Human growth hormone in children (UK guidance on GH prescribing)

Evidence Summary

Level I Evidence:

• GH therapy in GHD: Multiple RCTs show increased growth velocity and final height gain of 1.5-2 SD [9]
• GH therapy in Turner syndrome: Cochrane review demonstrates 5-10 cm height gain [10]
• GH therapy in SGA: Meta-analyses show final height gain of 0.5-1.5 SD [12]

Level II Evidence:

• GH in idiopathic short stature: Modest height gain (4-7 cm) but controversial due to cost-benefit ratio [20]

Landmark Studies:

• Ranke et al. (2016): KIGS database analysis (long-term GH outcomes in 83,000 children)
• Clayton et al. (2007): Turner syndrome management guidelines

---

11. Examination Focus (MRCPCH)

Viva Questions and Model Answers

Viva Point: Q1: "A 7-year-old boy is referred with short stature. How would you assess him?"

Model Answer:

"I would take a systematic approach beginning with a detailed auxological assessment:

History: I'd explore growth from birth - birth parameters, previous measurements from the red book, pattern of growth. I'd ask about pubertal development, nutritional intake, symptoms of chronic disease, and systemic review. Family history is crucial - I'd ask about parental heights and delayed puberty in the family.

Examination: I'd perform accurate anthropometry using a stadiometer - three measurements of height, weight, and BMI. I'd plot these on UK-WHO growth charts and calculate growth velocity if serial measurements available. I'd also calculate mid-parental height to assess if his height is appropriate for family.

I'd examine for dysmorphic features, body proportions (sitting height, arm span), pubertal staging using Tanner criteria, and look for signs of chronic disease.

Interpretation: I'd assess three key questions:

1. Is he truly short (below -2 SD)?
2. Is his growth velocity normal (parallel to centiles)?
3. Is his height appropriate for mid-parental height?

If he's tracking parallel to centiles with normal velocity and height consistent with short parents, this suggests familial short stature and reassurance is appropriate. If he's crossing centiles downward, this indicates pathology and I'd proceed to investigations including FBC, coeliac screen, thyroid function, bone age, and IGF-1."

Viva Point: Q2: "What is the difference between familial short stature and constitutional delay?"

Model Answer:

"Both are normal variants accounting for 80-90% of short children, but they differ in key aspects:

The key discriminator is bone age: normal in FSS, delayed in CDGP. Constitutional delay is a diagnosis of delayed maturation tempo - the child will eventually catch up and reach normal height, just 2-4 years later than peers."

Viva Point: Q3: "What are the indications for growth hormone therapy?"

Model Answer:

"GH therapy is indicated when licensed and clinically appropriate. The main licensed indications are:

1. Growth hormone deficiency (confirmed by low IGF-1 and peak GH less than 7 μg/L on two provocation tests, ideally with MRI showing pituitary pathology)

2. Turner syndrome (regardless of GH status; improves final height by 5-10 cm)

3. Chronic renal insufficiency (pre-transplant)

4. Prader-Willi syndrome

5. SGA without catch-up growth (birth weight/length < -2 SD, height < -2.5 SD at age ≥4 years)

6. SHOX gene deficiency

Controversial indication: Idiopathic short stature (height < -2.25 SD, no identified cause). Modest height gain (4-7 cm) but raises ethical issues about medicalizing normality.

GH is NOT indicated for familial short stature or constitutional delay (normal variants).

Before starting GH, I'd ensure diagnosis is robust, explain realistic expectations (typical gain 1-2 SD in final height), and counsel regarding daily injections and monitoring requirements."

Viva Point: Q4: "A girl with short stature has a bone age of 10 years but chronological age of 13 years. What does this suggest?"

Model Answer:

"A bone age delayed by 3 years suggests delayed skeletal maturation. In a 13-year-old girl, the differential includes:

1. Constitutional delay of growth and puberty (most likely if she's tracking parallel to centiles, family history of late development, and puberty is also delayed)

2. Hypothyroidism (would also expect weight gain, constipation, fatigue; check TSH/free T4)

3. Growth hormone deficiency (would expect progressive centile crossing; check IGF-1, consider provocation tests)

4. Chronic disease (malnutrition, coeliac, inflammatory bowel disease, chronic kidney disease)

5. Psychosocial deprivation

The key is to integrate bone age with growth velocity and pubertal staging. If she has normal velocity and delayed puberty, CDGP is likely. If velocity is reduced (centile crossing), pathology is more likely and I'd investigate accordingly.

Her predicted adult height should be calculated using the Bayley-Pinneau tables (bone age method) to reassure her that final height will likely be normal despite current short stature."

---

Common OSCE Stations

Station 1: Growth Chart Interpretation

• Candidate given growth chart with serial measurements
• Asked to interpret pattern, calculate MPH, suggest diagnosis

Examinertips:

• Always calculate growth velocity (cm/year)
• Identify centile crossing vs parallel tracking
• State MPH calculation and target range
• Suggest most likely diagnosis based on pattern

Station 2: Examination of Child with Short Stature

• Candidate asked to examine child (actor or mannequin)
• Focus on anthropometry, dysmorphic features, proportions, pubertal staging

Examinertips:

• Introduce yourself, gain consent
• Measure height correctly (explain technique even if simulated)
• Comment on body proportions (sitting height, arm span)
• Describe any dysmorphic features systematically
• Always perform Tanner staging (sensitively, with chaperone)

Station 3: Explaining Diagnosis to Parents

• Candidate asked to explain familial short stature or constitutional delay to parent (actor)
• Focus on reassurance, growth prediction, psychosocial support

Examinertips:

• Use simple language, avoid jargon
• Show growth chart to illustrate tracking
• Explain predicted adult height
• Address parental concerns (bullying, treatment)
• Offer resources and follow-up

---

12. Patient/Parent Explanation (Layperson Language)

"Why is my child short?"

Most children who are shorter than average are perfectly healthy. There are two common reasons:

1. Familial Short Stature ("Runs in the Family")

Your child is short because you or your partner (or both) are shorter than average. It's in the genes - just like having brown eyes or curly hair. Your child is growing at a normal speed, just along a lower line on the growth chart. They'll be a shorter adult, similar to you.

What to do: Nothing! Your child is healthy. We'll check their growth every year to make sure they stay on track.

---

2. Constitutional Delay ("Late Bloomer")

Your child is a "late developer"

• they'll hit their growth spurt and puberty a few years later than their friends. Right now they may be one of the shortest in the class, but by age 18-20, they'll catch up and reach a normal adult height.

What to do: Be patient. We can show you predictions that prove they'll catch up. If it's really affecting their confidence (especially boys), we can offer a short course of hormone treatment to give them a temporary boost while they're waiting.

---

When to worry (and when we investigate further):

We investigate if:

• Your child is falling down the growth chart (getting shorter compared to other children their age)
• Your child is extremely short (much shorter than you'd expect even for your family)
• Your child has other symptoms (tiredness, tummy pain, headaches)
• Your child looks different (unusual facial features, very short arms/legs)

What investigations might we do?

• Blood tests (to check for thyroid problems, gut problems like coeliac disease, or hormone levels)
• X-ray of the hand (tells us their "bone age"
• helps predict adult height)
• Sometimes, hormone tests or scans if we're worried about the pituitary gland (the hormone control center in the brain)

Growth hormone treatment: This is a daily injection that helps children who don't make enough growth hormone. It's very effective for children who truly need it, but it's not a "magic bullet" for all short children. We only use it when there's a medical reason.

The most important thing: Your child's health and happiness matter more than their height. Many perfectly healthy adults are short and live fulfilling lives.

---

13. References

1. Rogol AD, Hayden GF. Etiologies and early diagnosis of short stature and growth failure in children and adolescents. J Pediatr. 2014;164(5 Suppl):S1-14. doi:10.1016/j.jpeds.2014.02.027

2. Grimberg A, et al. Guidelines for Growth Hormone and Insulin-Like Growth Factor-I Treatment in Children and Adolescents: Growth Hormone Deficiency, Idiopathic Short Stature, and Primary Insulin-Like Growth Factor-I Deficiency. Horm Res Paediatr. 2016;86(6):361-397. doi:10.1159/000452150

3. Lindsay R, Feldkamp M, Harris D, et al. Utah Growth Study: growth standards and the prevalence of growth hormone deficiency. J Pediatr. 1994;125(1):29-35. doi:10.1016/s0022-3476(94)70117-2

4. Wit JM, Clayton PE, Rogol AD, et al. Idiopathic short stature: definition, epidemiology, and diagnostic evaluation. Growth Horm IGF Res. 2008;18(2):89-110. doi:10.1016/j.ghir.2007.11.004

5. Oostdijk W, Grote FK, de Muinck Keizer-Schrama SM, Wit JM. Diagnostic approach in children with short stature. Horm Res. 2009;72(4):206-217. doi:10.1159/000236082

6. Stalman SE, Hellinga I, van Dommelen P, et al. Application of the Dutch, Finnish and British screening guidelines in a cohort of children with growth failure. Horm Res Paediatr. 2015;84(6):376-382. doi:10.1159/000441144

7. Wright CM, Cheetham TD. The strengths and limitations of parental heights as a predictor of attained height. Arch Dis Child. 1999;81(3):257-260. doi:10.1136/adc.81.3.257

8. Sisley S, Trujillo MV, Khoury J, Backeljauw P. Low incidence of pathology detection and high cost of screening in the evaluation of asymptomatic short children. J Pediatr. 2013;163(4):1045-1051. doi:10.1016/j.jpeds.2013.04.002

9. Growth Hormone Research Society. Consensus guidelines for the diagnosis and treatment of growth hormone (GH) deficiency in childhood and adolescence: summary statement of the GH Research Society. J Clin Endocrinol Metab. 2000;85(11):3990-3993. doi:10.1210/jcem.85.11.6984

10. Gravholt CH, Andersen NH, Conway GS, et al. Clinical practice guidelines for the care of girls and women with Turner syndrome: proceedings from the 2016 Cincinnati International Turner Syndrome Meeting. Eur J Endocrinol. 2017;177(3):G1-G70. doi:10.1530/EJE-17-0430

11. Sedlmeyer IL, Palmert MR. Delayed puberty: analysis of a large case series from an academic center. J Clin Endocrinol Metab. 2002;87(4):1613-1620. doi:10.1210/jcem.87.4.8395

12. Clayton PE, Cianfarani S, Czernichow P, et al. Management of the child born small for gestational age through to adulthood: a consensus statement of the International Societies of Pediatric Endocrinology and the Growth Hormone Research Society. J Clin Endocrinol Metab. 2007;92(3):804-810. doi:10.1210/jc.2006-2017

13. Quintos JB, Salas P, Harbison MD. Thyroid hormone replacement in hypothyroid children with growth failure. J Pediatr Endocrinol Metab. 2005;18(10):985-989. doi:10.1515/jpem.2005.18.10.985

14. Tanner JM, Goldstein H, Whitehouse RH. Standards for children's height at ages 2-9 years allowing for heights of parents. Arch Dis Child. 1970;45(244):755-762. doi:10.1136/adc.45.244.755

15. Marshall WA, Tanner JM. Variations in pattern of pubertal changes in girls. Arch Dis Child. 1969;44(235):291-303. doi:10.1136/adc.44.235.291

16. Soliman AT, De Sanctis V, Elalaily R. Testosterone therapy in adolescent boys with constitutional delay of growth and development. Metabolism. 2012;61(3):351-356. doi:10.1016/j.metabol.2011.10.007

17. Hill ID, Dirks MH, Liptak GS, et al. Guideline for the diagnosis and treatment of celiac disease in children: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. J Pediatr Gastroenterol Nutr. 2005;40(1):1-19. doi:10.1097/00005176-200501000-00001

18. Cianfarani S, Tondinelli T, Spadoni GL, et al. Height velocity and IGF-I assessment in the diagnosis of childhood onset GH insufficiency: do we still need a second GH stimulation test? Clin Endocrinol (Oxf). 2002;57(2):161-167. doi:10.1046/j.1365-2265.2002.01591.x

19. Greulich WW, Pyle SI. Radiographic Atlas of Skeletal Development of the Hand and Wrist. 2nd ed. Stanford University Press; 1959.

20. Deodati A, Cianfarani S. Impact of growth hormone therapy on adult height of children with idiopathic short stature: systematic review. BMJ. 2011;342:c7157. doi:10.1136/bmj.c7157

---

14. Appendix A: Growth Velocity Reference Values

Normal Growth Velocity by Age

Interpretation:

• Growth velocity less than 25th centile for age = abnormal
• Sustained velocity less than 4 cm/year (age 4-10) = pathological

---

15. Appendix B: Tanner Staging Quick Reference

Boys (Genital and Pubic Hair Staging)

Genital Stage:

• G1 (Prepubertal): Testicular volume less than 4 ml
• G2: Testicular volume 4-8 ml; scrotum and penis enlarge slightly
• G3: Testicular volume 9-12 ml; penis lengthens
• G4: Testicular volume 13-20 ml; penis lengthens and broadens; glans develops
• G5 (Adult): Testicular volume > 20 ml; adult genitalia

Pubic Hair Stage:

• PH1: None
• PH2: Sparse, lightly pigmented
• PH3: Darker, coarser, spreading
• PH4: Adult type but smaller area
• PH5: Adult distribution including medial thighs

Girls (Breast and Pubic Hair Staging)

Breast Stage:

• B1 (Prepubertal): No palpable breast tissue
• B2: Breast bud palpable; areola enlarges
• B3: Breast and areola enlarge, no contour separation
• B4: Areola and nipple form secondary mound
• B5 (Adult): Adult contour; areola recessed to breast contour

Pubic Hair Stage: Same as boys (PH1-5)

Average Ages (UK):

• Thelarche (breast development): 10.5-11 years
• Menarche: 12.5-13 years
• Testicular enlargement: 11.5-12 years

---

16. Appendix C: Red Flags Requiring Urgent Referral

---

17. Appendix D: Growth Chart Centile Interpretation

UK-WHO Growth Charts:

• 99.6th centile = +2.67 SD
• 98th centile = +2 SD
• 91st centile = +1.33 SD
• 75th centile = +0.67 SD
• 50th centile (median) = 0 SD
• 25th centile = -0.67 SD
• 9th centile = -1.33 SD
• 2nd centile = -2 SD (definition of short stature)
• 0.4th centile = -3 SD (severe short stature)

Clinical Interpretation:

• Tracking between 2nd-98th centile: Normal range
• Below 2nd centile: Short stature (but 2.3% of normal population fall here)
• Crossing 2 centile spaces downward: Pathological growth faltering (investigate)
• Parallel tracking: Normal variant (FSS or CDGP) if velocity normal

---

18. Appendix E: Common Pitfalls in Assessment

Pitfall 1: Relying on parental self-reported heights

• Solution: Measure parents directly whenever possible (self-report often inaccurate by 2-5 cm)

Pitfall 2: Single height measurement to diagnose short stature

• Solution: Always obtain serial measurements to calculate growth velocity; pattern more informative than single point

Pitfall 3: Ordering "routine bloods" on all short children

• Solution: Reserve investigations for abnormal velocity or height < -3 SD; avoid over-investigation of normal variants

Pitfall 4: Diagnosing GHD based on low IGF-1 alone

• Solution: IGF-1 is screening test only; GHD requires low IGF-1 + abnormal GH provocation tests + clinical/auxological correlation

Pitfall 5: Forgetting to correct for prematurity

• Solution: Correct age for prematurity until age 2 years (e.g., 1 year chronological age born at 32 weeks = 10 months corrected age)

Pitfall 6: Missing Turner syndrome in tall girls

• Solution: Turner syndrome can present with normal height in childhood (especially mosaics); always karyotype girls with unexplained short stature

Pitfall 7: Not considering psychosocial short stature

• Solution: Always explore home environment; ask about school, social services involvement, safeguarding concerns

Pitfall 8: Using wrong growth charts

• Solution: Use syndrome-specific charts for Turner, Down, achondroplasia; use ethnicity-appropriate charts where available

---

19. Appendix F: Mid-Parental Height Worked Examples

Example 1: Boy

• Father's height: 172 cm
• Mother's height: 158 cm
• MPH = (172 + 158 + 13) / 2 = 171.5 cm
• Target range = 171.5 ± 10 cm = 161.5-181.5 cm

Interpretation: If boy's predicted adult height (based on bone age) is 165 cm, this falls within target range → consistent with familial short stature (parents also short).

---

Example 2: Girl

• Father's height: 180 cm
• Mother's height: 168 cm
• MPH = (180 + 168 - 13) / 2 = 167.5 cm
• Target range = 167.5 ± 10 cm = 157.5-177.5 cm

Interpretation: If girl's current height at age 10 is 125 cm (9th centile) and predicted adult height is 155 cm, this falls below target range → suggests pathology (parents are tall, so familial short stature unlikely).

---

20. Appendix G: GH Provocation Test Protocols

Insulin Tolerance Test (ITT)

Indication: Gold standard for GHD diagnosis

Contraindications: Epilepsy, severe cardiac disease, hypoadrenalism (unless covered with hydrocortisone)

Protocol:

1. Fasting from midnight
2. IV access established
3. Baseline samples: Glucose, GH, cortisol (time 0)
4. Insulin dose: 0.05-0.15 units/kg IV bolus (lower dose if suspected hypopituitarism)
5. Samples: Glucose and GH at 0, 15, 30, 45, 60, 90 minutes
6. Endpoint: Symptomatic hypoglycaemia (sweating, tachycardia) + glucose less than 2.2 mmol/L
7. Safety: 50% dextrose and glucagon available; continuous monitoring

Interpretation:

• Peak GH less than 7 μg/L = GHD
• Peak cortisol less than 500 nmol/L suggests ACTH deficiency

---

Glucagon Stimulation Test

Indication: Alternative if ITT contraindicated

Protocol:

1. Fasting 4 hours
2. Baseline: GH, glucose, cortisol
3. Glucagon dose: 0.03 mg/kg IM or SC (max 1 mg)
4. Samples: GH, glucose at 0, 30, 60, 90, 120, 150, 180 minutes
5. Side effects: Nausea, vomiting common (warn patient)

Interpretation: Peak GH less than 7 μg/L = GHD

---

(End of Document - Total Lines: 1,368)